Brick Planter against Block Fence

So we build a patio in the backyard and are about to put in a block wall using regular 4x8x16 block. What I'm wondering is if we build a brick planter about 2 1/2 or 3ft high, about roughly 20 or 24 inches deep and about 16ft long it leaves me with a few questions.

1: Can I just use the block wall as the backer for the planter?

2: What would be the best option for brick, do I need specific sizes or would a standard 4" brick work for the layers of the planter wall to support any issues with the weight of the dirt?